It is currently difficult for remote collaborators to work together in full color on arbitrary surfaces in a natural way. For instance, remote collaborators cannot easily share a physical document (e.g., a blank paper, magazine, architectural diagram) or a whiteboard, draw on it, annotate it, and see each other as they perform these actions (e.g., point, gesture, circle, and so forth). While some technologies for collaboration exist (e.g., tablet PCs, slates, instrumented surfaces, and digital surfaces with dedicated embedded cameras), they often require specialized and instrumented surfaces.